The Bunyip is a legendary animal for the Australian aborigenes. But in the 19th century, there were Bunyip sightings. In 1847 a young herdsmen saw a Long-necked Bunyip while he was looking for some cows in a flooded area. Here is the report made by George Hobler, reporter to the Sydney Morning Herald. It was about as big as a six months' old calf, of a dark brown colour, a long neck, and long pointed head; it had large ears which pricked up when it perceived him (the herdsmen); had a thick mane of hair from the head down the neck, and two large tusks. He turned to run away, and this creature equally alarmed ran off too, and from glance he took at it he describes it as having an awkward shambling gallop; the forequarters of the animal were very large in proportion to the hindquarters, and it had a large tail.
In 1852, another one was saw in lake Tiberias, Tasmania. It had a dog face. It was described as having a bulldog face, a 4-4½ feet lenght, and was saw swimming on the river, before to go away out of sight.
In 1872, another one was saw in Midgeon Lagoon by 3 men. Here is the report:
Half as long again as an ordinary retriever dog; the hair all over its body was jet-black and shining, its coat was very long, the hair spreading out on the surface of the water for about 5 inches, and floating loosely as the creature rose and fell by its own motion. I could not detect any tail, and the hair about its head was too long and glossy to admit of my seeing its eyes; the ears were well marked.
What was this? Among the hypothesis, there is the Diprotodon, an old marsupial today extinct. It may also be seals, which could have make their way inside the continent and became prisoneer of the swamps of Australia.
SOURCES: http://www.cryptozoology.com/bunyip/bunyip.html
Cryptozoologix 2001